Estimation of Radiation Dose Received in Skull X-Rays in ...

International Journal of Science and Research (IJSR) ISSN (Online): 2319-7064

Index Copernicus Value (2013): 6.14 | Impact Factor (2013): 4.438

Volume 4 Issue 10, October 2015

www.ijsr.net Licensed Under Creative Commons Attribution CC BY

Estimation of Radiation Dose Received in Skull X-

Rays in Emergency Radiology Department

Yousif Mohamed Y. Abdallah1, Noora E. Omer

2, Nesrin A. M. Mohamoud

3, Mashal Abdallah

4

1Department of Radiological Sciences and Medical Imaging, Majmaah University,

Prince Megreen Bin Abdel-aziz Road, Majmaah 11954, Saudi Arabia

2Sudan Academy of Science, Sudan Atomic Energy Commission, Elgamaa Street, Khartoum, Sudan

3Radiology Department, Sarat Abida General Hospital, Saudi Arabia

4Hager Specialized Clinic, Damam, Saudi Arabia

Abstract: Diagnostic X-ray examinations play an important role in the health care of the population. These examinations may

involve significant irradiation of the patient and probably represent the largest man-made source of radiation exposure for the

population. This study was performed in Emergency department of Khartoum teaching hospital in June 2015. This study performed to

assess the effective dose (ED) received in lumbosacral radiographic examination and to analyze effective dose distributions among

radiological departments under study. The study was performed in Khartoum teaching hospital, covering x-ray units and a sample of

50 patients. The following parameters were recorded age, weight, height, body mass index (BMI) derived from weight (kg) and (height

(m)) and exposure factors. The dose was measured for skull x-rays examination. For effective dose calculation, the entrance surface

dose (ESD) values were estimated from the x-ray tube output parameters for skull PA and lateral examinations. The ED values were

then calculated from the obtained ESD values using IAEA calculation methods. Effective doses were then calculated from energy

imparted using ED conversion factors proposed by IAEA. The results of ED values calculated showed that patient exposure were within

the normal range of exposure. The mean ED values calculated were 3.03 + 0.08 and 2.23 + 0.31 for skull PA and lateral examinations,

respectively. Further studies are recommended with more number of patients and using more two modalities for comparison.

Keywords: radiation dose, skull, x-rays, radiology department

1. Introduction

When the ionizing radiation penetrates the human body or an

object, it deposits energy. The energy absorbed from the

exposure to radiation is called a dose. Radiation dose

quantities are described in three ways: absorbed, equivalent,

and effective. The amount of energy deposited in a substance

(e.g., human tissue), is called the absorbed dose. The

absorbed dose is measured in a unit called the gray (Gy). A

dose of one gray is equivalent to a unit of energy (joule)

deposited in a kilogram of a substance. When radiation is

absorbed in living matter, a biological effect may be

observed. However, equal absorbed doses will not

necessarily produce equal biological effects. The effect

depends on the type of radiation (e.g., alpha: beta: gamma

etc) and the tissue or organ receiving the radiation. A

radiation weighting factor (WR) is used to equate different

types of radiation with different biological effectiveness. This

weighted absorbed quantity is called the equivalent dose and

is expressed in a measure called the (Sv). Sievert. Because

doses to workers and the public are so law, most reporting

and does measurements use the terms milisievert (mSv) and

microsievert (ϻSv) which are 1/1000 and 1/1000000 of a

sievert respectively. These smaller units of the sievert are

more convenient to use in occupational and public settings.

To obtain the equivalent dose, the absorbed dose is

multiplied by a specified radiation weighting factor (WR).

The equivalent dose provides a single unit which accounts

for the degree of harm of different types of radiation. [1].

The importance of plain radiography of the skull has

diminished in recent years due to the widespread availability

of imaging modalities such as computed tomography (CT)

and magnetic resonance imaging (MRI). These play a much

more significant role in the management of a patient with a

suspected intracranial pathology and either one would usually

be the modality of choice if such a pathology were suspected.

Plain radiography does, however, still play a significant role

in the management of patients with certain skeletal conditions

and, to a limited extent, in trauma, e.g. when a depressed or

penetrating injury is suspected or if the patient is difficult to

assess. Consequently, a significant number of referrals are

still received from accident and emergency department. In

order to produce high –quality images of the cranium and

minimize risk for the patient, the radiographer must have a

good understanding of the relevant anatomy, positioning

landmarks and equipments used for imaging. This should be

coupled with an ability to assess the patient’s ability and thus

apply the correct technique in any given situation. [2].

One of the typical human diagnostic techniques is x-ray the

x-ray examination depends on the range of radiation given to

the subject. The radiation from the x-ray depends primarily

upon the x-ray tube current (mA) tube voltage (kVp) and

exposure time (s). Assessment of radiation exposure

during X-ray examination are of great importance in

range of radiation given to the subject. Pediatrics radiology

should be governed with high professionals techniques to

minimize radiation hazard on children while they are

examined by X-ray parameters which involved in this

Paper ID: SUB158364 262





project are X-ray tube voltage, X-ray tube current and

the distance between the X-ray tube and patient's

skin(child). Different radiographic examinations representing

different radiographic techniques (tube voltage and current)

were recorded reflecting the variety in the radiation exposure

value computer program was used to calculate the entrance

skin exposure the results show that the radiation exposure

was still below the value of risk at this Time of exposure

ranging between (0.04-0.14) second. Arthritis is recognized

as a major public health problem. Arthritis and related

musculoskeletal disorders are frequently chronic, disabling

and painful. It is estimated that the total economic cost to the

U.S. of musculoskeletal conditions was over $65 billion in

1984. Indirect costs from lost earnings and services represent

a high proportion of these costs. These diseases represented

the second most common cause of comorbidity in the

Framingham Stu. The ideal mechanism for measuring the

incidence and prevalence of these chronic conditions and

their impact is through a survey which includes a physical

examination, radiographs, laboratory tests and other

procedures on a broad representative sample of the

population. Case identification of the arthritidesis a major

concern to those interested in obtaining complete and

accurate figures. Many individuals do not know and therefore

cannot report on what specific rheumatic disease affects

them. The American Rheumatism Association definitions of

a case are based on highly structured diagnostic criteria

which, for osteoarthritis and rheumatoid arthritis, require

radiologic evidence. With the emphasis in this survey on the

health of the elderly, NHANES III provides a particularly

appropriate context and population for the study of

musculoskeletal conditions. The major diseases to be

identified are rheumatoid arthritis, osteoarthritis and gout.

Cases will be defined by use of questions on characteristic

symptoms of the various disease; a physician's examination.

Focusing on pain, tenderness, swelling and deformities of

specified joints; x-rays of the hands and wrists, and knees;

and various serological analyses, including rheumatoid factor

and C-reactive protein. In addition to assessing the

prevalence of the rheumatic disease, it is important to

measure the burden of the diseases on the daily life of

individuals. This information is necessary to establish health

priorities and to monitor the effectiveness of interventions in

rheumatic disease. A series of questions that cover mobility,

physical activity and ability to care for oneself are included

to determine the extent of functional impairment (Andriacchi

et al, 2002).

2. Materials and Methods

A total of 50 patients were examined in two radiology

departments in Khartoum teaching hospital. The data were

collected using a sheet for all patients in order to maintain

consistency of the information. The following parameters

were recorded age, weight, height, body mass index (BMI)

derived from weight (kg)/ (height (m)) and exposure

parameters were recorded. The dose was measured for

lumbosacral x-rays examination. The examinations were

collected according to the availability.

This study involved patients undergoing skull radiographic

examinations in the emergency department at Khartoum

Teaching Hospital. The radiographic equipment used was

Toshiba imaging system. It has a Polydoros LX 50 Lite high

frequency generator with a general radiographic X-ray tube

Opti 150/30/50HC. The target angle for the X-ray tube was

12°, and the measured ripple for tube potential was in the

region of 1%. Total filtration for the X-ray system

wasmeasure as 2.7 mm of aluminum equivalent. A single

exposure control system was available for use in the under-

table or vertical position. Preliminary work will establish that

lateral lumbar spine examinations will carry out in two

different ways depending on the clinical condition of the

patient. Patients with good mobility were lying on their side

on the X-ray table with the X-ray beam vertically above

them. Immobile patients was lying supine on a trolley in

front of a vertical bucky with the X-ray beam horizontal.

Both techniques used exposure control and a tube potential

range of between 85 kV and 100 kV depending on the patient

size. Average tube potential for both techniques will be in the

region of 93 kV. With dose audit, there were difficulties in

complying with the requirement to collect dose data for

patients of a particular weight range (50–90 kg) within the

busy environment of an emergency department. In this case,

the decision took to increase the sample size to

approximately 50 patients and to exclude those of very large

or small build but not require the collection of patient weight

information. Separate sets of DAP dose data were collected

for each of the two radiographic techniques.

ESD which is defined as the absorbed dose to air at the

center of the beam including backscattered radiation,

measured for all patients using mathematical equation in

addition to output factor and patient exposure factors. The

exposure to the skin of the patient during standard

radiographic examination or fluoroscopy can be measured

directly or estimated by a calculation to exposure factors

used and the equipment specifications from formula below:

(1)

Where:

(OP) is the output in mGy/ (mA) of the X-ray tube at 80 kV

at a focus distance of 1 m normalized to 10 mA s, (kV) the

tube potential,( mA) the product of the tube current (mA) and

the exposure time(s), (FSD) the focus-to-skin distance (in

cm). (BSF) the backscatter factor, the normalization at 80 kV

and 10 mAs was used as the potentials across the X-ray tube

and the tube current are highly stabilized at this point. BSF is

calculated automatically by the Dose Cal software after all

input data are entered manually in the software. The tube

output, the patient anthropometrical data and the

radiographic parameters (kVp, mA s, FSD and filtration) are

initially inserted in the software. The kinds of examination

and projection are selected afterwards.

3. The results

For the group of patients where age distribution was

measured, 12 % of patients were within the 0-9 years age

range, 20 % of patients were within the 10-19 years age








range, 2 % of patients were within the 40-49 years age range,

6 % of patients were within the 50-59 years age range, 6 % of

patients were within the 60-69 years age range and 6 % of

patients were within the 70-79 years age range. The key

parameters for this group are shown in Table 1.

Table 1: Age distribution for both genders among the study

sample Age Group (years) Male Female

0-9 5 1

10-19 8 2

20-29 14 2

30-39 7 0

40-49 1 1

50-59 2 1

60-69 0 3

70-79 2 1

For the group of patients where Body Mass Index (BMI) was

measured, 12 % of patients were within the 5 + 10.6 BMI

range, 20 % of patients were within the 22 + 0.05 BMI range,

32 % of patients were within the 20 + 0.003 BMI range, 14

% of patients were within the 27 + 0.03 BMI range, 2 % of

patients were within the 26 + 0.3 BMI range, 6 % of patients

were within the 27 + 0.01 BMI range, 6 % of patients were

within the 37 + 0.06 BMI range, 6 % of patients were within

the 23 + 0.03 BMI range and 6 % of patients were within the

23 + 0.03 BMI range. The key parameters for this group are

shown in Table 2.

Table 2: The mean and standard deviation of Body mass

index distribution for both genders among the study sample Age Group (years) Body Mass Index (BMI)

0-9 5±10.6

10-19 22±0.05

20-29 20±0.003

30-39 27±0.03

40-49 26±0.3

50-59 27±0.01

60-69 37±0.06

70-79 23±0.03

For the group of patients where x-rays exposure factors (kVp

and mAs) was measured, 12 % of patients were within the

51.5 + 3.73 (kVp), 49.5 + 10.1 (Second), 110+ 22.36 (mA)

range, 20 % of patients were within the 58.1 + 5.52 (kVp),

51.7 + 7.42 (Second), 142+ 48.40 (mA) range, 32 % of

patients were within the 61.6 + 7.83 (kVp), 62.2 + 26.2

(Second), 171.2+ 38.1 (mA) range, 14 % of patients were

within the 61.5 + 7.48 (kVp), 65.1 + 24.7 (Second), 140+

37.06 (mA) range, 2 % of patients were within the 70.0 + 0.0

(kVp), 67 + 0.0 (Second), 200+ 0.0 (mA) range, 6 % of

patients were within the 72.6 + 14.6 (kVp), 52 + 8.49

(Second), 186.6+ 18.96 (mA) range, 6 % of patients were

within the 67.3 + 7.77 (kVp), 62.0 + 6.03 (Second), 200+ 0.0

(mA) range, 6 % of patients were within the 51.5 + 3.73

(kVp), 49.5 + 10.1 (Second), 110+ 22.36 (mA) range and 6

% of patients were within the 67.0 + 5.10 (kVp), 82.33 +

27.33 (Second), 166.5+ 1.49.36 (mA) range. The key

parameters for this group are shown in Table 3-3.

Table 3: Shows the mean and standard deviation of exposure

factors used for knee joint examination in the study sample

Age group mA

mean± SD

kVp

mean±SD

Second

mean±sD

0-9 110.0 ± 22.36 51.5 ± 3.73 49.5 ± 10.11

10-19 142.0 ± 48.40 58.1 ± 5.52 51.7 ± 7.42

20-29 171.25 ± 38.1 61.68 ± 7.83 62.18 ± 26.24

30-39 140.0 ± 37.03 61.57 ± 7.48 65.14 ± 24.78

40-49 200.0 ± 0.0 70.0 ± 0.0 67.0 ± 4.0

50-59 186.66 ± 18.96 72.66 ± 14.60 52.0 ± 8.49

60-69 200.0 ± 0.0 67.33 ± 7.77 62.0 ± 6.03

Figure 1. Correlation between Body weight (Kg) and dose

Figure 2. Correlation between Body Mass Index and dose

Table 4: Exposure factors, number of films and dose values

for Lumbosacral exam Projection Dose (mrem)

(Mean + SD)

ICRP Dose

mrem (mSv)

Postroanterior (PA) 3.03 +0.08 3 (0.03)

Lateral 2.23 + 0.31 1 (0.01)

4. Conclusion

This experimental study performed to measure of dose

received in skull x-ray examination. In the emergency

department, patients undergoing skull radiography

examination are positioned either lying on their side on an X-

ray table with the X-ray beam vertical or lying supine on a

trolley with the X-ray examination have been evident from

various international dose surveys. Reference dose levels

provide a framework to reduce this variability and aid

optimization of radiation protection. A total of 50 patients

were examined in two radiology departments in Khartoum

teaching hospital. The data were collected using a sheet for

all patients in order to maintain consistency of the

information. The following parameters were recorded age,

weight, height, body mass index (BMI) derived from weight






(kg)/ (height (m)) and exposure parameters were recorded.

The dose was measured for lumbosacral x-rays examination.

The examinations were collected according to the

availability. This study involved patients undergoing skull

radiographic examinations in the emergency department at

Khartoum Teaching Hospital. The radiographic equipment

used Toshiba imaging system. It has a Polydoros LX 50 Lite

high frequency generator with a general radiographic X-ray

tube Opti 150/30/50HC. The target angle for the X-ray tube

was 12°, and the measured ripple for tube potential will be in

the region of 1%. Total filtration for the X-ray system

measured as 2.7 mm of aluminum equivalent. Finally, in this

study, it was found that doses for skull for the entire

examination were higher. The ESDs for conventional

radiology were lower in AP than those for lateral projection.

Unlike the previous studies, the dose in skull radiography

was higher in conventional radiography compared to other

techniques. Recently digital and computed radiography are

becoming more popular due to the important advantage of

digital imaging is cost and access. The image quality met the

criteria of the departments for all investigation. The findings

of this study are therefore neither completely unexpected nor

in contradiction with those of other trials. Therefore the

importance of dose optimization during conventional

radiology imaging must be considered.

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Authors Profile

Yousif Mohamed Yousif Abdallah received the

B.S., M.Sc. and PhD degrees nuclear medicine and

Radiation Therapy from College of Medical

radiological Science, Sudan University of Science and

Technology in 2005, 2009 and 2013 respectively. He

was professor (assistant) in College of Medical radiological

Science, Sudan University of Science and Technology from

September 2006 to March 2015. Form March 2015 till now, he is

now Professor (assistant) in department of Radiological Sciences

and medical Imaging, College of Medical Applied Sciences,

Majmaah University, Saudi Arabia.

Noora E. Omer received the B.Sc. in Physics from university of

Khartoum and M.Sc. in Medical Physics in Sudan Academy of

Science in 2009 and 2014 respectively.

Nesrin A. M. Mohamoud received the B.Sc. College of Medical

radiological Science, Sudan University of Science and Technology.

From 2005–2007, she was working in College of Medical

radiological Science, Sudan University of Science and Technology

as assistant teaching in Diagnostic radiology department. Now she

is working in radiology department of Sarat Abida General

Hospital, Saudi Arabia.

Mashael Abdallah received the B.S., M.Sc. degrees in medical

physics from College of Medical radiological Science, Sudan

University of Science and Technology. She is now Hager

Specialized Clinic, Damam, Saudi Arabia.


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